In June end, a small US firm-Vaxart-made a surprise announcement: Its underdeveloped vaccine had been selected by the Trump government to be part of Operation Warp Speed, an initiative to quickly develop drugs to combat Covid-19.

Vaxart’s shares soared. Company insiders, who had received stock options worth a few million dollars weeks ago, saw the value of those awards increase sixfold. And a hedge fund that partly controlled the company walked away with more than $200 million in instant profits.

Across the pharmaceutical and medical industries, senior executives and board members are capitalizing on the future vaccine market which could be billions of dollars.

They are making millions of dollars after announcing positive developments, including support from the government, in their efforts to fight Covid-19.

After such announcements, insiders from at least 11 companies — most of them smaller firms whose fortunes often hinge on the success or failure of a single drug — have sold shares worth well over $1 billion since March, according to figures compiled for The New York Times by Equilar, a data provider.

In some cases, company insiders are profiting from regularly scheduled compensation or automatic stock trades. But in other situations, senior officials appear to be pouncing on opportunities to cash out while their stock prices are sky high. And some companies have awarded stock options to executives shortly before market-moving announcements about their vaccine progress.

Several Indian pharma companies are also in the vaccine and drug development stages. It is unclear how much profits they accumulated even as their candidate is yet to be out.